BALTIMORE — At Everest Greenish Grocery, a brightly lit store on a faded corner of this city, nothing is more popular than a chocolate-flavored little cigar. They are displayed just above the Hershey bars along with their colorful cigarillo cousins — white grape, strawberry, pineapple and Da Bomb Blueberry. And they were completely sold out by 9 one recent evening, snapped up by young people dropping by for a snack or stopping in during a night of bar hopping.

“Sorry, no more chocolate,” the night clerk, Qudrad Bari, apologetically told a young woman holding a fruit drink.

In 2009, Congress passed a landmark law intended to eliminate an important gateway to smoking for young people by banning virtually all the flavors in cigarettes that advocates said tempted them. Health experts predicted that the change would lead to deep reductions in youth smoking. But the law was silent on flavors in cigars and a number of other tobacco products, instead giving the Food and Drug Administration broad discretion to decide whether to regulate them.

Four years later, the agency has yet to assert that authority. And a rainbow of cheap flavored cigars and cigarillos, including some that look like cigarettes, line the shelves of convenience stores and gas stations, often right next to the candy. FDA officials say they intend to regulate cigars and other tobacco products, but they do not say how or when. Smoking opponents contend that the agency’s delay is threatening recent progress in reducing smoking among young people.

Cigarette sales are down by a third over the past decade, according to federal data, but critics of the agency say the gains are being offset by the rise of cheaper alternatives like cigars, whose sales have doubled over the same period and whose flavored varieties are smoked overwhelmingly by young people. Loose tobacco and cigars expanded to 10 percent of all tobacco sold in the United States in 2011, up from just 3 percent in 2000, federal data show.

“The 20th century was the cigarette century, and we worked very hard to address that,” said Gregory N. Connolly, the director of the Center for Global Tobacco Control at the Harvard School of Public Health. “Now the 21st century is about multiple tobacco products. They’re cheap. They’re flavored. And some of them you can use anywhere.”

The FDA is now wrestling with how to exercise its authority over an array of other tobacco products. In recent weeks, for example, it sent warning letters to several companies that it says are disguising roll-your-own tobacco as pipe tobacco, a practice that industry analysts say has become a common way to avoid federal taxes and FDA regulation.

“The giant has finally awoken and hopefully will do its job,” said Ron Bernstein, the chief executive of Liggett Vector Brands, a cigarette producer that is worried about unfair competition from cigar makers and others.

Mitchell Zeller, 55, a public interest lawyer who became the director of the FDA’s Center for Tobacco Products this spring, acknowledged in an interview that the emergence of new tobacco products meant a new look was needed.

“What we’ve seen in the past 10 years is this remarkable transformation of the marketplace,” Zeller said. “There are products being sold today — unregulated products — that literally did not exist 10 years ago.”

But new rules have to be grounded in scientific evidence, he said, and written to withstand legal challenges. The tobacco industry won a recent court fight against graphic images on cigarette labels.

As for the criticism that the agency has been slow to act, Zeller said, “Message received.”

But the FDA’s careful approach exasperates smoking opponents.

“We shouldn’t need 40 years of study to figure out that chocolate- and grape-flavored cigars are being smoked by young people,” said Matthew L. Myers, the president of the Campaign for Tobacco-Free Kids. Traditional handmade cigars were seen as a luxury for older men, but much of the recent growth has been in products sold in convenience stores to low-income customers. Flavored cigars now represent more than half of all convenience store and gas station cigar sales, up nearly 40 percent since 2008, according to Nielsen market data analyzed by Cristine Delnevo, a tobacco researcher at Rutgers University.

A three-pack of Good Times flavored cigarillos at Everest costs 99 cents, an alluring price for the store’s clientele: young, poor African-Americans.

On a recent evening, Bari, a native of Pakistan, was in a generous mood. He had just broken his Ramadan fast with sweet tea and was helping a customer with the last 30 cents needed for a pack of Newports. But he said flavored cigars were actually more popular in his store than cigarettes. Sometimes people pay for them with spare change.

Jay Jackson, a 19-year-old nursing assistant in hospital scrubs, rarely has the $6.50 for a pack of cigarettes, which she also smokes, but can usually come up with a dollar for the kind of cigar she likes. Flavors improve the taste of cigars that are otherwise so harsh they make her light headed, she said, paying Bari for two — chocolate and cherry.

Bari said he remembered only strawberry, vanilla and chocolate when he first arrived 10 years ago. “Now look at this,” he said, motioning toward the cigar shelf disapprovingly. Some companies are producing small filtered cigars that look like cigarettes in brown wrappers, avoiding the federal taxes and FDA regulation required for cigarettes. Bernstein, the cigarette producer, contended that such cigars made up much of the recent increase in cigar sales. A typical pack of 20 costs about $2, compared with about $6 for a pack of cigarettes.

Tobacco in cigars is cured by a different method than tobacco in cigarettes. And cigars come in a wrapper made of tobacco, while cigarettes are wrapped in paper. Smaller cigars popular among young people tend to be inhaled more, making the health risks similar to cigarettes.

Nationally, about 1 in 6 18- to 24-year-olds smoke cigars, federal research shows, compared with only 2 percent of people over 65. More than half of the younger users smoke flavored cigars, with the highest rates among the poorest and least educated.

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Those are familiar circumstances in certain parts of Baltimore, where life expectancy for men can be as low as 63 years, a level last seen for all American men in the 1940s. The smoking rate here is double the national one — a pattern that Devin Miles, a high school junior who started smoking cigarettes when he was 10, said was obvious at his school.

“Everybody smokes, even the teachers,” he said.

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Cigar producers say they are bracing for FDA action, even as sales have flattened in the last few years, dampened by new taxes. But they question a flavor ban, pointing out that the FDA has yet to prohibit the most common flavor, menthol, in cigarettes and that chewing tobacco still comes in flavors.

“We continue to ask the question, ‘What’s the rationale?’” said Joe Augustus, a spokesman for Swisher International, a cigar producer. Flavors have existed “since the beginning of time,” he said, and are popular with “the guys who are cutting your lawn and fixing your car.”

There is also evidence that cigar purchases are related to marijuana use. In a survey of 5,000 middle and high school students in Massachusetts in 2003, researchers found that about a fifth were using cigar wrappers to smoke marijuana.

Bari, the night clerk, said many of his customers used the wrappers for marijuana. “It’s the younger generation,” he said. “Your sister’s crying, your daughter’s crying, you don’t care.”

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One customer, Torri Stevens, a 19-year-old who said she worked at a strip club in Washington, said she sometimes smoked as many as 12 blunts a day, a name for marijuana in a cigar wrapper that is associated with Phillies Blunt, a cigar brand.

Black youths were the one group that registered a rise in cigar smoking nationally. Twelve percent of black high school students smoked cigars in 2011, compared with 7 percent in 2009, the Centers for Disease Control said.

Maryland, where the legal age to buy cigarettes is 18, did its own survey and found that cigar smoking had increased across the entire high school population. It is now one of at least six states where cigar smoking among youths now equals or surpasses cigarette smoking, according to the CDC.

Alarmed officials started a public education campaign. A website, TheCigarTrap.com, shows an ice cream truck adorned with a giant lit cigar and children running after it.

On a recent night at Everest Greenish Grocery, Bari sold cigars to patrons of a nearby transvestite bar and people who were just leaving work.

Trayvon Henderson, 19, was still wearing his McDonald’s uniform when he stopped in for a chocolate cigarillo. Cigars are stylish, he said, and some of his favorite rappers smoke them.

“If they take away the flavor, it would be a problem,” he said, cigarillo in hand. “I’d probably stop smoking them. Or maybe I’d go back to cigarettes.”